Two orthogonal hybrid antennas for the LTE MIMO operation in the smartphone are presented. The two antennas (one open-slot antenna and one inverted-F antenna) are disposed orthogonally to each other. The open-slot antenna comprises two open slots of different lengths and is disposed parallel and close to the bottom edge of the smartphone. The open-slot antenna operates in the 698~960 MHz and 1710~2690 MHz bands as a main antenna for the LTE/WWAN operation. The inverted-F antenna has a total length of 90 mm and is disposed along one side edge of the device ground plane. The inverted-F antenna can fit in a narrow ground clearance of 1 mm between the display panel and the casing of the smartphone. The side-edge antenna is able to cover the frequency ranges of 824~960 MHz and 1710~2690 MHz for the LTE operation such as in band 5, 8, 10, 25, and 40. Owing to the orthogonal alignment of the two antennas, good envelope correlation coefficients of less than 0.07 are obtained. The ergodic channel capacity is calculated to reach about 9.3~10.7 bps/Hz at 20-dB signal-to-noise ratio. Details of the MIMO antenna structure and its operating principle are described. Experimental results of the fabricated prototype are presented and discussed. Effects of the display panel and user’s hand on the MIMO performance are also analyzed.